summaryrefslogtreecommitdiff
path: root/tools/perf/util/util.c
blob: 4f561e5e41622fbfe11dea9f7ae06e31c259953a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
// SPDX-License-Identifier: GPL-2.0
#include "util.h"
#include "debug.h"
#include "event.h"
#include <api/fs/fs.h>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <dirent.h>
#include <fcntl.h>
#include <inttypes.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <linux/capability.h>
#include <linux/kernel.h>
#include <linux/log2.h>
#include <linux/time64.h>
#include <linux/overflow.h>
#include <unistd.h>
#include "cap.h"
#include "strlist.h"
#include "string2.h"

/*
 * XXX We need to find a better place for these things...
 */

const char *input_name;

bool perf_singlethreaded = true;

void perf_set_singlethreaded(void)
{
	perf_singlethreaded = true;
}

void perf_set_multithreaded(void)
{
	perf_singlethreaded = false;
}

int sysctl_perf_event_max_stack = PERF_MAX_STACK_DEPTH;
int sysctl_perf_event_max_contexts_per_stack = PERF_MAX_CONTEXTS_PER_STACK;

int sysctl__max_stack(void)
{
	int value;

	if (sysctl__read_int("kernel/perf_event_max_stack", &value) == 0)
		sysctl_perf_event_max_stack = value;

	if (sysctl__read_int("kernel/perf_event_max_contexts_per_stack", &value) == 0)
		sysctl_perf_event_max_contexts_per_stack = value;

	return sysctl_perf_event_max_stack;
}

bool sysctl__nmi_watchdog_enabled(void)
{
	static bool cached;
	static bool nmi_watchdog;
	int value;

	if (cached)
		return nmi_watchdog;

	if (sysctl__read_int("kernel/nmi_watchdog", &value) < 0)
		return false;

	nmi_watchdog = (value > 0) ? true : false;
	cached = true;

	return nmi_watchdog;
}

bool test_attr__enabled;

bool perf_host  = true;
bool perf_guest = false;

void event_attr_init(struct perf_event_attr *attr)
{
	if (!perf_host)
		attr->exclude_host  = 1;
	if (!perf_guest)
		attr->exclude_guest = 1;
	/* to capture ABI version */
	attr->size = sizeof(*attr);
}

int mkdir_p(char *path, mode_t mode)
{
	struct stat st;
	int err;
	char *d = path;

	if (*d != '/')
		return -1;

	if (stat(path, &st) == 0)
		return 0;

	while (*++d == '/');

	while ((d = strchr(d, '/'))) {
		*d = '\0';
		err = stat(path, &st) && mkdir(path, mode);
		*d++ = '/';
		if (err)
			return -1;
		while (*d == '/')
			++d;
	}
	return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
}

static bool match_pat(char *file, const char **pat)
{
	int i = 0;

	if (!pat)
		return true;

	while (pat[i]) {
		if (strglobmatch(file, pat[i]))
			return true;

		i++;
	}

	return false;
}

/*
 * The depth specify how deep the removal will go.
 * 0       - will remove only files under the 'path' directory
 * 1 .. x  - will dive in x-level deep under the 'path' directory
 *
 * If specified the pat is array of string patterns ended with NULL,
 * which are checked upon every file/directory found. Only matching
 * ones are removed.
 *
 * The function returns:
 *    0 on success
 *   -1 on removal failure with errno set
 *   -2 on pattern failure
 */
static int rm_rf_depth_pat(const char *path, int depth, const char **pat)
{
	DIR *dir;
	int ret;
	struct dirent *d;
	char namebuf[PATH_MAX];
	struct stat statbuf;

	/* Do not fail if there's no file. */
	ret = lstat(path, &statbuf);
	if (ret)
		return 0;

	/* Try to remove any file we get. */
	if (!(statbuf.st_mode & S_IFDIR))
		return unlink(path);

	/* We have directory in path. */
	dir = opendir(path);
	if (dir == NULL)
		return -1;

	while ((d = readdir(dir)) != NULL && !ret) {

		if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, ".."))
			continue;

		if (!match_pat(d->d_name, pat)) {
			ret =  -2;
			break;
		}

		scnprintf(namebuf, sizeof(namebuf), "%s/%s",
			  path, d->d_name);

		/* We have to check symbolic link itself */
		ret = lstat(namebuf, &statbuf);
		if (ret < 0) {
			pr_debug("stat failed: %s\n", namebuf);
			break;
		}

		if (S_ISDIR(statbuf.st_mode))
			ret = depth ? rm_rf_depth_pat(namebuf, depth - 1, pat) : 0;
		else
			ret = unlink(namebuf);
	}
	closedir(dir);

	if (ret < 0)
		return ret;

	return rmdir(path);
}

static int rm_rf_a_kcore_dir(const char *path, const char *name)
{
	char kcore_dir_path[PATH_MAX];
	const char *pat[] = {
		"kcore",
		"kallsyms",
		"modules",
		NULL,
	};

	snprintf(kcore_dir_path, sizeof(kcore_dir_path), "%s/%s", path, name);

	return rm_rf_depth_pat(kcore_dir_path, 0, pat);
}

static bool kcore_dir_filter(const char *name __maybe_unused, struct dirent *d)
{
	const char *pat[] = {
		"kcore_dir",
		"kcore_dir__[1-9]*",
		NULL,
	};

	return match_pat(d->d_name, pat);
}

static int rm_rf_kcore_dir(const char *path)
{
	struct strlist *kcore_dirs;
	struct str_node *nd;
	int ret;

	kcore_dirs = lsdir(path, kcore_dir_filter);

	if (!kcore_dirs)
		return 0;

	strlist__for_each_entry(nd, kcore_dirs) {
		ret = rm_rf_a_kcore_dir(path, nd->s);
		if (ret)
			return ret;
	}

	strlist__delete(kcore_dirs);

	return 0;
}

int rm_rf_perf_data(const char *path)
{
	const char *pat[] = {
		"data",
		"data.*",
		NULL,
	};

	rm_rf_kcore_dir(path);

	return rm_rf_depth_pat(path, 0, pat);
}

int rm_rf(const char *path)
{
	return rm_rf_depth_pat(path, INT_MAX, NULL);
}

/* A filter which removes dot files */
bool lsdir_no_dot_filter(const char *name __maybe_unused, struct dirent *d)
{
	return d->d_name[0] != '.';
}

/* lsdir reads a directory and store it in strlist */
struct strlist *lsdir(const char *name,
		      bool (*filter)(const char *, struct dirent *))
{
	struct strlist *list = NULL;
	DIR *dir;
	struct dirent *d;

	dir = opendir(name);
	if (!dir)
		return NULL;

	list = strlist__new(NULL, NULL);
	if (!list) {
		errno = ENOMEM;
		goto out;
	}

	while ((d = readdir(dir)) != NULL) {
		if (!filter || filter(name, d))
			strlist__add(list, d->d_name);
	}

out:
	closedir(dir);
	return list;
}

size_t hex_width(u64 v)
{
	size_t n = 1;

	while ((v >>= 4))
		++n;

	return n;
}

int perf_event_paranoid(void)
{
	int value;

	if (sysctl__read_int("kernel/perf_event_paranoid", &value))
		return INT_MAX;

	return value;
}

bool perf_event_paranoid_check(int max_level)
{
	return perf_cap__capable(CAP_SYS_ADMIN) ||
			perf_cap__capable(CAP_PERFMON) ||
			perf_event_paranoid() <= max_level;
}

static int
fetch_ubuntu_kernel_version(unsigned int *puint)
{
	ssize_t len;
	size_t line_len = 0;
	char *ptr, *line = NULL;
	int version, patchlevel, sublevel, err;
	FILE *vsig;

	if (!puint)
		return 0;

	vsig = fopen("/proc/version_signature", "r");
	if (!vsig) {
		pr_debug("Open /proc/version_signature failed: %s\n",
			 strerror(errno));
		return -1;
	}

	len = getline(&line, &line_len, vsig);
	fclose(vsig);
	err = -1;
	if (len <= 0) {
		pr_debug("Reading from /proc/version_signature failed: %s\n",
			 strerror(errno));
		goto errout;
	}

	ptr = strrchr(line, ' ');
	if (!ptr) {
		pr_debug("Parsing /proc/version_signature failed: %s\n", line);
		goto errout;
	}

	err = sscanf(ptr + 1, "%d.%d.%d",
		     &version, &patchlevel, &sublevel);
	if (err != 3) {
		pr_debug("Unable to get kernel version from /proc/version_signature '%s'\n",
			 line);
		goto errout;
	}

	*puint = (version << 16) + (patchlevel << 8) + sublevel;
	err = 0;
errout:
	free(line);
	return err;
}

int
fetch_kernel_version(unsigned int *puint, char *str,
		     size_t str_size)
{
	struct utsname utsname;
	int version, patchlevel, sublevel, err;
	bool int_ver_ready = false;

	if (access("/proc/version_signature", R_OK) == 0)
		if (!fetch_ubuntu_kernel_version(puint))
			int_ver_ready = true;

	if (uname(&utsname))
		return -1;

	if (str && str_size) {
		strncpy(str, utsname.release, str_size);
		str[str_size - 1] = '\0';
	}

	if (!puint || int_ver_ready)
		return 0;

	err = sscanf(utsname.release, "%d.%d.%d",
		     &version, &patchlevel, &sublevel);

	if (err != 3) {
		pr_debug("Unable to get kernel version from uname '%s'\n",
			 utsname.release);
		return -1;
	}

	*puint = (version << 16) + (patchlevel << 8) + sublevel;
	return 0;
}

int perf_tip(char **strp, const char *dirpath)
{
	struct strlist *tips;
	struct str_node *node;
	struct strlist_config conf = {
		.dirname = dirpath,
		.file_only = true,
	};
	int ret = 0;

	*strp = NULL;
	tips = strlist__new("tips.txt", &conf);
	if (tips == NULL)
		return -errno;

	if (strlist__nr_entries(tips) == 0)
		goto out;

	node = strlist__entry(tips, random() % strlist__nr_entries(tips));
	if (asprintf(strp, "Tip: %s", node->s) < 0)
		ret = -ENOMEM;

out:
	strlist__delete(tips);

	return ret;
}

char *perf_exe(char *buf, int len)
{
	int n = readlink("/proc/self/exe", buf, len);
	if (n > 0) {
		buf[n] = 0;
		return buf;
	}
	return strcpy(buf, "perf");
}

void perf_debuginfod_setup(struct perf_debuginfod *di)
{
	/*
	 * By default '!di->set' we clear DEBUGINFOD_URLS, so debuginfod
	 * processing is not triggered, otherwise we set it to 'di->urls'
	 * value. If 'di->urls' is "system" we keep DEBUGINFOD_URLS value.
	 */
	if (!di->set)
		setenv("DEBUGINFOD_URLS", "", 1);
	else if (di->urls && strcmp(di->urls, "system"))
		setenv("DEBUGINFOD_URLS", di->urls, 1);

	pr_debug("DEBUGINFOD_URLS=%s\n", getenv("DEBUGINFOD_URLS"));

#ifndef HAVE_DEBUGINFOD_SUPPORT
	if (di->set)
		pr_warning("WARNING: debuginfod support requested, but perf is not built with it\n");
#endif
}

/*
 * Return a new filename prepended with task's root directory if it's in
 * a chroot.  Callers should free the returned string.
 */
char *filename_with_chroot(int pid, const char *filename)
{
	char buf[PATH_MAX];
	char proc_root[32];
	char *new_name = NULL;
	int ret;

	scnprintf(proc_root, sizeof(proc_root), "/proc/%d/root", pid);
	ret = readlink(proc_root, buf, sizeof(buf) - 1);
	if (ret <= 0)
		return NULL;

	/* readlink(2) does not append a null byte to buf */
	buf[ret] = '\0';

	if (!strcmp(buf, "/"))
		return NULL;

	if (strstr(buf, "(deleted)"))
		return NULL;

	if (asprintf(&new_name, "%s/%s", buf, filename) < 0)
		return NULL;

	return new_name;
}

/*
 * Reallocate an array *arr of size *arr_sz so that it is big enough to contain
 * x elements of size msz, initializing new entries to *init_val or zero if
 * init_val is NULL
 */
int do_realloc_array_as_needed(void **arr, size_t *arr_sz, size_t x, size_t msz, const void *init_val)
{
	size_t new_sz = *arr_sz;
	void *new_arr;
	size_t i;

	if (!new_sz)
		new_sz = msz >= 64 ? 1 : roundup(64, msz); /* Start with at least 64 bytes */
	while (x >= new_sz) {
		if (check_mul_overflow(new_sz, (size_t)2, &new_sz))
			return -ENOMEM;
	}
	if (new_sz == *arr_sz)
		return 0;
	new_arr = calloc(new_sz, msz);
	if (!new_arr)
		return -ENOMEM;
	if (*arr_sz)
		memcpy(new_arr, *arr, *arr_sz * msz);
	if (init_val) {
		for (i = *arr_sz; i < new_sz; i++)
			memcpy(new_arr + (i * msz), init_val, msz);
	}
	*arr = new_arr;
	*arr_sz = new_sz;
	return 0;
}

#ifndef HAVE_SCHED_GETCPU_SUPPORT
int sched_getcpu(void)
{
#ifdef __NR_getcpu
	unsigned int cpu;
	int err = syscall(__NR_getcpu, &cpu, NULL, NULL);

	if (!err)
		return cpu;
#else
	errno = ENOSYS;
#endif
	return -1;
}
#endif

#ifndef HAVE_SCANDIRAT_SUPPORT
int scandirat(int dirfd, const char *dirp,
	      struct dirent ***namelist,
	      int (*filter)(const struct dirent *),
	      int (*compar)(const struct dirent **, const struct dirent **))
{
	char path[PATH_MAX];
	int err, fd = openat(dirfd, dirp, O_PATH);

	if (fd < 0)
		return fd;

	snprintf(path, sizeof(path), "/proc/%d/fd/%d", getpid(), fd);
	err = scandir(path, namelist, filter, compar);
	close(fd);
	return err;
}
#endif